Molecular regulation of ZmMs7 required for maize male fertility and development of a dominant male-sterility system in multiple species.

Understanding the molecular basis of male sterility and developing practical male-sterility systems are essential for heterosis utilization and commercial hybrid seed production in crops. Here, we report molecular regulation by genic male-sterility gene maize male sterility 7 (ZmMs7) and its application for developing a dominant male-sterility system in multiple species. ZmMs7 is specifically expressed in maize anthers, encodes a plant homeodomain (PHD) finger protein that functions as a transcriptional activator, and plays a key role in tapetal development and pollen exine formation. ZmMs7 can interact with maize nuclear factor Y (NF-Y) subunits to form ZmMs7-NF-YA6-YB2-YC9/12/15 protein complexes that activate target genes by directly binding to CCAAT box in their promoter regions. Premature expression of ZmMs7 in maize by an anther-specific promoter p5126 results in dominant and complete male sterility but normal vegetative growth and female fertility. Early expression of ZmMs7 downstream genes induced by prematurely expressed ZmMs7 leads to abnormal tapetal development and pollen exine formation in p5126-ZmMs7 maize lines. The p5126-ZmMs7 transgenic rice and Arabidopsis plants display similar dominant male sterility. Meanwhile, the mCherry gene coupled with p5126-ZmMs7 facilitates the sorting of dominant sterility seeds based on fluorescent selection. In addition, both the ms7-6007 recessive male-sterility line and p5126-ZmMs7M dominant male-sterility line are highly stable under different genetic germplasms and thus applicable for hybrid maize breeding. Together, our work provides insight into the mechanisms of anther and pollen development and a promising technology for hybrid seed production in crops.

The potential agents from food for preventing leukopenia induced by benzene: garlic preparations.

Leukopenia is the early clinical manifestation of benzene poisoning. The aim of our research was to evaluate the preventive effects of three kinds of garlic preparations on benzene induced leukopenia. The mouse model of Leukopenia was established with benzene orally. At the same time, mice were administrated with garlic homogenate (GH), garlic oil (GO) or diallyl trisulfide (DATS) as preventional measures. The counts of white blood cells (WBC), the organ indexes, pathological examinations, blood biochemical parameters, weight gains, and food intakes were evaluated to observe the protective effect and potential adverse events. The results demonstrated that the counts of WBC increased by 144.04%, 140.07%, and 148.34%, respectively, after intervention by GH (400 mg/kg), GO (60 mg/kg) and DATS (30 mg/kg), compared with that in the model group. The spleen and thymus indexes in the benzene model group were 44.99% and 54.04% lower than those in the blank control group, the number of spleen nodules reduced and the thymus atrophy, which were restored by three garlic preparations at different degree. The results suggested that the three preparations all could prevent the leukopenia and protect the organ injuries induced by benzene. However, the spleen index and weight gains revealed that GH and GO brought more adverse events than DATS.